Musculoskeletal pain is a health challenge with various treatment strategies. The study has been accomplished with the aim to reveal the effect of mineral water with different mineral content on musculoskeletal pain and related symptoms experienced. A randomized controlled single-blinded parallel-group study has been performed (145 participants with pain; 5 groups). The duration of treatment was 2 weeks, whereas follow-up has taken 3 months. Change in pain after a single procedure and the pain parameters with related symptoms during the study period have been measured. The effect size using Cohen's d has been estimated. Small effect (0.2-0.4) on pain has been distinguished after each mineral water procedure. Tap water procedures have been effective in 60% of cases. Twenty grams per liter water baths have had a small effect on pain intensity and tender points, body flexibility, and spinal mobility, and a medium one on sleep quality, and reduced CRP. Forty grams per liter water has had a small effect on pain intensity, frequency, and spinal mobility, and a medium one on flexibility, fatigue, and sleep quality, and reduced ESR. Sixty grams per liter water has had a small effect on pain parameters and fatigue, and a medium one on flexibility and sleep quality, and reduced ESR. The effect lasting up to 2 months has been identified mostly in the 60 g/L group. Tap water has had a short time effect on pain intensity and tender points. There have not been any changes of sufficient significance identified in the control group and any differences between mineral water groups. Sufficient difference between mineral and tap water groups has been determined in pain intensity, spinal mobility, and sleep quality, whereas in the case of the control group, significant difference in pain intensity and frequency, flexibility, and spinal mobility has been identified. The consumption of pain medication has significantly decreased in all mineral water groups. The total mineral content of the water has no significant influence on the reduction of musculoskeletal pain. Mineral water baths have small effect on pain and medium effect on other musculoskeletal disease-related symptoms and pain medication consumption lasting up to 3 months; it is more beneficial than tap water or no treatment for the improvement of symptoms associated with musculoskeletal diseases. Even single balneotherapy procedure results in small pain reduction.

Keywords: Balneology; Geothermal water; Hydrotherapy; Musculoskeletal pain.